neuromuscular Flashcards
EMG findings neuropathy
longer AP duration and amplitude
EMG finding myopathy
decreased AP duration and amplitude
EMG myasthenia gravis
dimished response to repetitive stimulation
EMG LEMS
incremental response to repetitive stimulation
which auto-antibodies are formed in myasthenia gravis (MG)
antibodies to ACh receptors on muscles (post-synaptic)
who usually gets MG
women (30) or men 65
assoc MG
thymoma,
symptoms MG
weakness worst throughout day // extraocular: diplopia, proximal muscle weakness, dysphagia
first symptoms MG (usually)
eyes
imaging tests MG
EMG + CT thorax
blood tests MG
CK normal // antibodies to AChR // tensolin test - give IV edrophonium to reduce symptoms
mx MG
1 = AChE inhibitors eg pyridostigmine // 2 = immunosuppression eg pred, azathioprine, cyclosporine // 3 = thymectomy
mx myasthenic crisis
plasmapheresis, IV Ig
what is MG crisis
resp muscles not working
auto-antibodies in LEMS
against pre-synaptic Ca channels in PNS
assoc with LEMS
small cell lung cancer!!!
symptoms LEMS
proximal muscle weakness which improves with exercise // hyporeflexia // autonomic symptoms // eyes usually spared
invx LEMS
EMG = incremental response to repetitive stimuli
mx LEMS
pred +/- azathioprine // 3,4-diaminopyridine // IV Ig
what organism causes botulism
clostridium botulinum
what toxin is releaesed in botulism and what does it do
botulinum –> irreversibly blocks release of ACh
symptoms botulism
flaccid paralysuis, diplopia, ataxia, bulbar palsy
mx botulism
antitoxin only of early enough - supportive care
what drugs can exacerbate MG
BB // penicillamine // procainamide // lithium / phenytoin // abx
inheritance myotonic dystrophy + types
dominant // DM1 = CTG repeat chromosome 19 // DMT = repeat expansion chromosome 3
main difference between myotonic dystrophy DM1 and DM2
DM1 chromosome 19 + distal weakness // DM2 chromosome 3 + proximal weakness + congenital form not seen
what age does myotonic dystrophy present
20-30
assoc thymoma
myasthenia graves // dermatomyositis // SLE // 60-70
complications thymoma
airway obstruction // cardiac tamponade
